Domestic appliance



May 14, 1957 M. E. FRY

DOMESTIC APPLIANCE Filed Nov. 9, 1954 "f 1 lmina!! W n www' 2Sheets-Sheet 1 IN V EN TOR.

HIS ATTORNEY May 14, 1957 M. E. FRY

DOMESTIC APPLIANCE 2 Sheets-Sheet 2 Filed Nov. 9, 1954 J/\";y\

IN VEN TOR. )mM-a y HLS` ATTORNEY United States Patent() DOMESTICAPPLIANCE Millard E. I 'ry, Dayton, Ohio, assignor to General MotorsCorporation, Detroit, Mich., a corporation of Dela- Ware ApplicationNovember 9, 1954, Serial No. 467,715 6 Claims. (Cl. 219-37) Thisinvention relates to a domestic appliance and more particularly tosurface heaters of ranges provided with thermostatic controls.

Thermostatic control of surface heaters has many advantages inconvenience in cooking, but manufacturers have been slow in developing asimple practical form and arrangement for production.

It is an object of my invention to provide a simple practical form ofthermostatic control which is accurate and reliable and permits easyremoval and/or disassembly of the parts for easy and rapid cleaning.

It is another object of my invention to provide a simple practical formof thermostatic control embodied in a surface heater which is readilyinterchangeable with a non-thermostatically controlled surface heater.

These and other objects are attained in the first form shown byproviding a conventional combined trim ring and support arrangementincluding a sheet metal threearmed support resting upon screw headsprojecting from the ring. The central portion of the three-armed supportis provided with a spring cage which contains a spring above which isresilently mounted a ilat disc-shaped thermostat bulb. The surfaceheater shown is of the spiral sheathed type which surrounds the centralraised portion of the three-armed support containing the spring cage.Any flat bottomed vessel resting upon the surface heater will contactand depress the thermostat bulb which is held up against the bottom ofthe vessel by the spring within the cage. The thermostat bulb isconnected through a resilient capillary tube with a diaphragm operatedswitch means connected in series with the surface heater and adjusted tocontrol the temperatures to which the vessel is heated and maintained.The capillary tube connection extends from the thermostat bulb throughthe hollow interior of one of the arms of the support. In this form itextends alongside the tangential portion of the heater provided with ahinge connection with the range top.

vIn a second form, the drip pan and trim ring are cornbined. The heaterand three armed support is located within the pan. The side wall of thepan is provided with an aperture large enough to pass both the heaterand its support. One arm of the support has a loose coupled connectionwith an adjacent bracket extending from the range top.

The resiliently mounted thermostat bulb in the center of the support isconnected by acapillary tube extending along within one support armbeneath the loose coupling to'` a diaphragm'l operated switch `meansbeneath thc range top.

f lFurther objects and advantages of the present invention will bevapparent from the following description, reference being had to theaccompanying drawings, wherein a preferred form of the invention isclearly shown.

v In the drawings:

' Figure l is a top view of a surface heater embodying one form of myinvention;

1 Figure 2 is asectionalview taken substantially along ICC 2 the lines2--2 of Figure l and including a wiring diagram;

Figure 3 is an enlarged fragmentary sectional view taken substantiallyalong the lines 3--3 of Figure 2;

Figure 4 is a top view of a modied form of thermostatically controlledsurface heater;

Figure 5 is a sectional view taken substantially along` the lines 5-5 ofFigure 4;

Figure 6 is a fragmentary sectional view taken substantially along thelines 6-6 of Figure 4; and

Figure 7 is a view in elevation of the form shown in Figures l to 3particularly showing the hinge connection between the heater and therange top.

Referring now more particularly to Figures l to 3 and 7 there is shown arange top 20 provided with a flanged surface heater opening 22Overlapping this flanged surface opening 22 is an ornamental trim ring24 having a large ornamental flange and a downwardly extendingcylindrical portion provided with an inturned flange 26 which supportsthe outturned flange 28 of the drip pan 3i) The drip pan 30 includes acentral overflow opening 32. The cylindrical wall of the trim ring 24 isprovided with three large headed Support screws located approximatelyapart.

The ends of the three arms of the heater support 36 rest upon thesethree screws 34. The three-armed heater support is formed of sheet metaland has a raised central portion 32 connecting directly with invertedU-shaped arms 36 to form a rigid lightweight structure, A sheathedtubular heater 40 which is triangular-shaped in cross section with thewide flat side uppermost is arranged in a spiral about the centralportion 38 and has a tangential downwardly extending round end portion42 extending through an opening in the side wall of the trim ring 24. Atits extreme end portion the round end 42 of the heater 4t) is providedwith a terminal 44. Between the terminal 44 and the aperture in the trimring 24, the round end portion 42 of the heater 4) is provided with ahinge connection 46 with the range top 2Q. The pivoting axis of thehinge connection is concentric with the round end portion 42.

The surface heater 40 has sheet metal projections 48 welded to itsbottom surface extending through apertures 50 in the top surface of thethreearmed support 36 as shown in Figure 2. This connects the heater 49permanently to the support 36. The central portion 38 of the support 36is provided with a central aperture 52 within which is located a iiatdisc-shaped thermostat bulb 54. As better shown in Figure 3, this bulb54 includes a flat inverted cup-shaped member 56 extending downwardlythrough the aperture 52 which may have an out wardly extending flange orprojections 58 serving as stop to limit the upward movement of the bulb54. Within the member 56`is a shallow cup-shaped member 60 fittingtightly within the member 56 and being sealed thereto by solder or othersuitable material to provide an enclosed space for a hydraulicthermostatic liquid. The cup-shaped member 60 has a sealed off chargingtube 62 for filling the interior of the bulb 54 with hydraulicthermostatic liquid.

lts interior also connects to the capillary tube 64 extending downwardlythrough a central bottom opening in the spring cage. 66. The spring cage66 is in the vform of a cylindrical member having its upper end fastened-to the central portion 38 outside the opening 52 and having an inwardlyturned flange at the bottom which supports the lower end of a lightcompression type coil spring 68. The upper end of this coil spring isheld within the rim of the inverted cup-shaped member 56 against thebottom of the shallow cup-shaped member 6l) as-is 'shown in- Figure 3.The capillarytube.64 extends downwardly through.thecentraliopening inthe springfca'ge andY Patented May `14:,

thence upwardly'through'the interior of one of the arms 315'I to'a.supporting' pin' 7d provided on` theY arm 36'; The

capillary tube from this point);V extends alongside the round endportion 42 of the heater 4i) and isI supported. by the, bracket 72welded to the terminal' portion 42 adjacent the.

hinge 46. This portion of the capillary tube 64 isrsubsta'rtiallyparallel to the axis of the end portion 42.

The capillary tube 64 extends beneath the range top to a diaphragmoperated switch means, 74 which includes a metal bellows '76 operating aswitch mechanism 73 connecting with a supply conductor Si? and aconductor S2 connecting withvtheterminal 44 for the heater 40. Theopening and closing temperatures of the switch means 78 are controlledby a temperature adjusting knob 84 to control the connection a-nddisconnection of the heater 4l) to and from the power' line S0 inlaccordance with the temperature of thethermostat bulb 54 adapted to beheld against the bottom of a vessel upon. the heater 40. The heaterv(itl-may include heating circuits 86 and 88 connecting with conductors9,1) and 92 each provided with` individual switch means connecting witha 117 volt supply conductor 94 and a 235 volt supply conductor 96. Thesedifferent connections make it possiblel to provide different heatingrates for the surface heater 4t) in addition to the thermostat controlprovided by the thermostat bulb 54, the capillary tube 64 and thediaphragm operated switch 74.

The arrangement of the capillary tube parallel to the end portion 42 ofthe heater makes it possible to readily clean the heater merely bytilting7 the heater 40 upwardly on its hinge connection 46. This raisesthe support 36 with it so that the drip pan may be removed for cleaningand the trim ring 24 is made accessible for cleaning without removal.

A modified form of the invention is shown in Figures 4 to 6. ln thisform there is provided a combined trim ring and drip pan 139 providedwith a continuous seamless integral rim 124 which has a suflicientlywide ange to overlap the portion of the range top 120 surrounding thesurface heater unit opening 121. The top is provided with a step-downange 122 immediately surrounding the aperture 121 for receiving thebowl-shaped portion of the drip pan 130. This drip pan 13G is providedwith a raised central outlet portion 132. The ange portion 122 includestwo arcuate segments upon which rest the shoulders 145 and 147 of thepan 130.

Two arms 149 and 151 of the three-armed support 135 rest upon theshoulders 147 and 145 as shown in Figures 4 and 5. The three-armedsupport 136 is formed of sheet metal and the arms are shaped in the formof an inverted U to provide stiffness. The support 136 includes a raisedcentral portion 13S having a centrally located .aperture through whichproiects the thermostat bulb 54. As `shown in Figures l to 3 the centralportion is provided with a spring cage 166 having its upper flangesriveted to the centrall portion 54. A compression type coil spring 168resiliently urges the bulb 54 upwardly into engagement with the bottomof the cooking vessel. The bulb 54 is connected by a capillary tube 164to a -switch arrangement similar to the switch arrangement 74 1n Figure2. The capillary `tube is connected to a diaphragm operated switch meanswhich is connected in series with the surface heater 14) as is shown inFigure 2.

The third arm 135 of the heater 140 is supported by a bracket 137fastened to the flange 122 by a screw 13,9. This bracket 137 projectswithinthe arm135 asshown in Figures 4V and 6. The arm 135 isloosely'connected to the bracket 137 by an inverted T-shapedconnector'165 which extends upwardly through adjacentslots in thesupportV 137 and the arm 135 and is provided with a cotter pin`extending through its aperture above the support 136 to provide a loosepivotal connection. The support 136 supports a tubular sheated type ofsurface heater 1411 arrangedin a flat spiral and shaped similarly to theheater vided with a hinge support similar to the hinge connection 46vshown in Figures l toY 3; The connector 165'is-provided with a loop atthe bottom through which extends the capillary tube 164.

This supports the intermediate portion of the tube 164 and limits itsbending stresses. The connector 165 prevents the removal of the support136 and also limits its movement so that the bendingY of the capillarytube 164 is greatly reduced. To remove the combined drip pan and trimring 131i there is provided an. aperture 141 in the vertical side wallof the drip pan.1130 on. either'side of and below the connector 165.This aperture is entirely below the rim 124. ToI remove. the drip panthe drip pan is lifted and then pulled directly away from the bracket137 and the pan. 130is: pulled away from the bracket 137 allowing thepan 124 to be removed with the surface heater 141i and its bracket 136passing through the aperture 141 as the pan 130 is being pulled upwardlyand' away from the bracket 137. The pan 130 can then readily be taken toa suitable sink for cleaning and can be readily replaced followingcleaning4 by passingl the heater 1,40 and its support 136 again throughthe aperture 141 until it fits in place in the aperture 121 in the rangetop 12) as shown in Figures 4 to 6. This arrangementV insures that thehousewife will not get her hands in the vicinity of the terminals of theheaters and also limits the bending upon the capillary tube 164. Thisprovides a simple arrangement.

The weight of any cooking utensil upon the surface heater 141) will betransmitted through the three-armed support 136 to theA shoulders 145and 147 to the flange 122 of the range top 121i. The bulb 54 willbepressed against the bottom of such a surface vessel by the spring 168.The expansion of the liquid in the bulb 154 will be suflicient when theproper temperature in the surface vessel is reached to operate thediaphragm operated switch under open position to discontinue the Howv ofcurrent through the heater 1441. This arrangement isalso excellent inappearance and very convenient.

In accordance with the provisions of Rule 78a, reference is made to thefollowing prior led applications: S. N. 344,867 tiled March 26, 1953,now Patent 2,754,403 issued July 10, 1956, and S. N. 368,895 led July20, 195,3, now Patent 2,754,405 issued July l0, 195.6.

While the form of embodiment of the inventiony as herein disclosedconstitutes a preferred form, it is to be.

understood that other forms might be adopted, as may come within thescope, of the claims which follow.

What is claimed is as follows:

1. An electric range including a top provided with a surface heateropening, a removable drip pan provided with an integral continousuninterrupted rim extending over the portions of said top bordering saidopening, an electric surface heater within said drip pan, said panhaving an elongated horizontal opening beneath the rim large enough topass said heater through it, said heater having its terminal portionextending through said opening, a pivotal connection between said heaterand said range top extending through said opening, a resiliently mountedthermostat bulb within said heater, a diaphragm operated switch meansassociated with said top, for controlling said heater, and a capillarytube extending from said bulb through said opening to said diaphragmoperated switch means.

2. An electric range including a top provided with a surface, heateropening, a removable drip pan provided with an integral continuousuninterrupted rim extending over the portions of said top bordering saidopening, an electric surface heater within said drip pan, a supportbeneath saidheater within said drip pan, said pan having an elongatedhorizontal opening beneath the rim large enough to pass said heater andsupport through it, a pivotal connectionV between saidl top andV saidsupport passing through said opening, a thermostat bulb resilientlymounted upon said Support within said heater, a

diaphragm operated switch means associated with said range top, forcontrolling said heater, a capillary tube extending from said bulb'through said opening to said diaphragm operated switch means.

3. An electric range including a top provided with a surface heateropening, a removable drip pan provided with an integral continuousuninterrupted rim extending over the portions of said top bordering saidopening, an electric surface heater within said drip pan, a supportbeneath said heater within said drip pan, said pan having an elongatedhorizontal opening beneath the rim large enough to pass said heater andsupport through it, said support including an endless loop surroundingan opening and arms extending outwardly from said loop, one of said armsbeing provided with a slot, said range top including a projectionextending adjacent said slot, and a loose coupling extending from saidprojection through said slot.

4. An electric range including a top provided with a surface heateropening, a removable drip pan provided with an integral continuousuninterrupted rim extending over the portions of said top bordering saidopening, an electric surface heater within said drip pan, a supportbeneath said heater Within said drip pan, said pan having an elongatedhorizontal opening beneath the rim large enough to pass said heater andsupport through it, said support including an endless loop surroundingan opening and arms extending outwardly from said loop, one of said armsbeing provided with a slot, said range top including a projectionextending adjacent said slot, and a loose coupling extending from saidprojection through said slot, a thermostat bulb resiliently mountedwithin said opening surrounded by said loop, a diaphragm operated switchmeans associated with said range top for controlling said heater, and acapillary tube connecting said bulb and said diaphragm operated switchmeans, said capillary tube having an intermediate portion extendingalong the arrn provided with said slot.

5. An electric range including a top provided with a surface heateropening, a removable drip pan provided with an integral continuousuninterrupted rim extending over the portions of said top bordering saidopening, an electric surface heater within said drip pan, a supportbeneath said heater within said drip pan, said pan having an elongatedhorizontal opening beneath the rim large enough to pass said heater andsupport through it, said support including an endless loop surroundingan opening and arms extending outwardly from said loop, one of said armsbeing provided with a slot, said range top in cluding a projectionextending adjacent said slot, and a loose coupling extending from saidprojection through said slot, a thermostat bulb resiliently mountedwithin said opening surrounded by said loop, a diaphragm operated switchmeans associated with said range top for controlling said heater, and acapillary tube connecting said bulb and said diaphragm operated switchmeans, said capillary tube having an intermediate portion extendingalong the arm provided with said slot and having a portion supported bysaid loose coupling..

6. An electric range including a top provided with a surface heateropening, an electric surface heater disposed in said opening, said topbeing provided with mounting means for pivotally supporting said surfaceheater for pivoting about a given axis, a thermostatic bulb resilientlymounted within said surface heater for pivotal movement with saidheater, said bulb having a surface for engaging the bottom of a utensilresting on said heater, a stationarily mounted diaphragm operated switchmeans associated with said range top for controlling said surfaceheater, and a capillary tube having one end communicating with theinterior of said thermostatic bulb and having an intermediate portionwith its longitudinal axis extending along and substantially parallel tosaid given axis for a substantial distance and connecting at itsopposite end to said diaphragm operated switch means whereby uponpivotal movement of said surface heater and said bulb relative to saidtop and switch means said intermediate portion of said capillary tube istwisted in torsion about its longitudinal axis.

References Cited in the le of this patent UNITED STATES PATENTS2,260,790 Russell Oct. 28, 1941 2,303,012 Weber et al Nov. 24, 19422,506,554 Tuttle May 2, 1950 2,668,899 Rutenber Feb. 9, 1954 2,699,487Turner Jan. 11, 1955

